Impaired ribosome biogenesis checkpoint activation induces p53-dependent MCL-1 degradation and MYC-driven lymphoma death

MYC-driven B-cell lymphomas are addicted to increased levels of ribosome biogenesis (RiBi), offering the potential for therapeutic intervention. However, it is unclear whether inhibition of RiBi suppresses lymphomagenesis by decreasing translational capacity and/or by p53 activation mediated by the impaired RiBi checkpoint (IRBC). Here we generated Eμ-Myc lymphoma cells expressing inducible short hairpin RNAs to either ribosomal protein L7a (RPL7a) or RPL11, the latter an essential component of the IRBC. The loss of either protein reduced RiBi, protein synthesis, and cell proliferation to similar extents. However, only RPL7a depletion induced p53-mediated apoptosis through the selective proteasomal degradation of antiapoptotic MCL-1, indicating the critical role of the IRBC in this mechanism. Strikingly, low concentrations of the US Food and Drug Administration-approved anticancer RNA polymerase I inhibitor Actinomycin D (ActD) dramatically prolonged the survival of mice harboring Trp53+/+;Eμ-Myc but not Trp53-/-;Eμ-Myc lymphomas, which provides a rationale for treating MYC-driven B-cell lymphomas with ActD. Importantly, the molecular effects of ActD on Eμ-Myc cells were recapitulated in human B-cell lymphoma cell lines, highlighting the potential for ActD as a therapeutic avenue for p53 wild-type lymphoma.

Human sperm decondensation in vitro is related to cleavage rate and embryo quality in IVF

PURPOSE

To investigate whether the ability of human spermatozoa to decondense in vitro in the presence of heparin (Hep) and glutathione (GSH) is related to assisted reproduction (ART) success.

METHODS

Cross-sectional pilot study involving male partners of 129 infertile couples undergoing ICSI with (45) or without (84) donor oocytes at two infertility clinics in CABA, Argentina, between October 2012 and December 2013. In vitro decondensation kinetics with Hep and GSH and DNA fragmentation (TUNEL) were determined on the same sample used for ICSI. The possible relationship of decondensation parameters (maximum decondensation and decondensation velocity) and TUNEL values with ART success was evaluated.

RESULTS

Embryo quality correlated positively with decondensation velocity (D60/D30) (Spearman's correlation, p < 0.05). According to D60/D30 values, patients were classified as slow decondensers (SlowD) (n = 68) or fast decondensers (FastD) (n = 61). Embryo quality was better in FastD (unpaired t test, p < 0.05). FastD and SlowD were subdivided according to use of donor oocytes. Among SlowD, biochemical and clinical pregnancy rates per transfer were significantly higher in donor (n = 19) vs. in non-donor (n = 31) cycles (Fisher's exact test, p < 0.05). TUNEL values were not related to embryo quality, but no clinical pregnancies or live births were achieved in TUNEL+ SlowD (n = 7).

CONCLUSION

Decondensation kinetics of human spermatozoa in vitro with Hep and GSH could be related to embryo quality and ART success.

Human adult neurogenesis across the ages: An immunohistochemical study

AIMS

Neurogenesis in the postnatal human brain occurs in two neurogenic niches; the subventricular zone (SVZ) in the wall of the lateral ventricles and the subgranular zone (SGZ) of the hippocampus. The extent to which this physiological process continues into adulthood is an area of ongoing research. This study aimed to characterize markers of cell proliferation and assess the efficacy of antibodies used to identify neurogenesis in both neurogenic niches of the human brain.

METHODS

Cell proliferation and neurogenesis were simultaneously examined in the SVZ and SGZ of 23 individuals aged 0.2-59 years, using immunohistochemistry and immunofluorescence in combination with unbiased stereology.

RESULTS

There was a marked decline in proliferating cells in both neurogenic niches in early infancy with levels reaching those seen in the adjacent parenchyma by 4 and 1 year of age, in the SVZ and SGZ, respectively. Furthermore, the phenotype of these proliferating cells in both niches changed with age. In infants, proliferating cells co-expressed neural progenitor (epidermal growth factor receptor), immature neuronal (doublecortin and beta III tubulin) and oligodendrocytic (Olig2) markers. However, after 3 years of age, microglia were the only proliferating cells found in either niche or in the adjacent parenchyma.

CONCLUSIONS

This study demonstrates a marked decline in neurogenesis in both neurogenic niches in early childhood, and that the sparse proliferating cells in the adult brain are largely microglia.

Effects of Healthy Families New York on the promotion of maternal parenting competencies and the prevention of harsh parenting

OBJECTIVES

This paper examines the effectiveness of the Healthy Families New York (HFNY) home visiting program in promoting parenting competencies and preventing maladaptive parenting behaviors in mothers at risk for child abuse and neglect.

METHODS

The study used microlevel observational assessments of mother-child interactions in the third wave of a randomized controlled trial to evaluate whether mothers who received home visiting services were more likely to exhibit positive parenting and less likely to display negative parenting behaviors than those who did not receive these services. Women were randomly assigned during pregnancy or shortly after the birth of the target child to an intervention group that was offered home visiting services or a control group that was given referrals to other services. At Year 3, 522 mother and child pairs were systematically observed while they interacted in semistructured tasks presenting varied parenting challenges. The study also sought to replicate a finding from Year 2, which revealed that program effects on harsh parenting were stronger among young, first-time mothers who were randomly assigned during pregnancy (the High Prevention Opportunity subgroup) than among the other mothers (the Limited Prevention Opportunity subgroup).

RESULTS

Results indicate that HFNY was effective in fostering positive parenting, such as maternal responsivity and cognitive engagement. With respect to negative parenting, HFNY mothers in the High Prevention Opportunity subgroup were less likely than their counterparts in the control group to use harsh parenting, while no differences were detected for the Limited Prevention Opportunity subgroup.

CONCLUSION

HFNY was successful in promoting positive parenting among mothers at risk for child abuse and neglect, which may reflect the program's strength-based approach. The replication of the High Prevention Opportunity subgroup as a moderator of program effects on harsh parenting further suggests that HFNY may be more useful for preventing the initiation rather than the recurrence of child abuse and neglect.

PRACTICE IMPLICATIONS

To optimize service delivery, HFNY should continue to focus on enhancing parent-child interactions, prioritize HFNY services for young, first-time mothers who are offered the program during pregnancy, and investigate effective strategies to reduce negative parenting practices among the Limited Prevention Opportunity subgroup.

Choice in a self-control paradigm: Quantification of experience-based differences

Previous quantitative models of choice in a self-control paradigm (choice between a larger, more-delayed reinforcer and a smaller, less-delayed reinforcer) have not described individual differences. Two experiments are reported that provide additional quantitative data on experience-based differences in choice between reinforcers of varying sizes and delays. In Experiment 1, seven pigeons in a self-control paradigm were exposed to a fading procedure that increased choices of the larger, more-delayed reinforcer through gradually decreasing the delay to the smaller of two equally delayed reinforcers. Three control subjects, exposed to each of the small-reinforcer delays to which the experimental subjects were exposed, but for fewer sessions, demonstrated that lengthy exposure to each of the conditions in the fading procedure may be necessary in order for the increase to occur. In Experiment 2, pigeons with and without fading-procedure exposure chose between reinforcers of varying sizes and delays scheduled according to a concurrent variable-interval variable-interval schedule. In both experiments, pigeons with fading-procedure exposure were more sensitive to variations in reinforcer size than reinforcer delay when compared with pigeons without this exposure. The data were described by the generalized matching law when the relative size of its exponents, representing subjects' relative sensitivity to reinforcer size and delay, were grouped according to subjects' experience.

Evaluation of the quality and treatability of leachate produced at a landfill connected to an urban waste composting and recovery plant at Alhendin (Granada, Spain)

The leachate produced at a landfill adjoining an urban waste composting and recovery plant at Alhendin (Granada, Spain) was sampled for a period of more than 3 years from February 2003 until July 2006. The main pollutant parameters (COD, BOD(5), solids, nitrogen, main anions and cations, pH, Eh and conductivity) were analysed with the aim of selecting the most effective treatment for the leachate. The results obtained showed high concentrations of different pollutants with COD and BOD(5) values up to 74,133 mg/L and 39,000 mg/L respectively. Seasonal changes in leachate composition were mainly attributed to differences in rainfall, temperatures, and evaporation rates. Our study classified the Alhendin landfill leachate as a partially stabilized leachate because of: (i) its management strategies (storage at artificial ponds and recirculation); (ii) the coexistence in the landfill of active and closed cells with wastes of different ages and at different decomposition phases. The leachate quality data obtained was statistically evaluated using various statistical tools. A good correlation was found between many of the parameters analysed, some of which also showed good linear regressions. Principal component analysis allowed the reduction of most of the parameters analysed to four components: Component 1 (K(+), Mg(2 +), FTS, VDS, VTS, Na(+) and Cl(-)), component 2 (BOD(5)), component 3 (TDS, TS, FDS and conductivity) and component 4 (pH, FSS, Eh and VSS). The results obtained are valuable for the selection of the best leachate treatment option. A combination of a physicochemical treatment and a fixed film biological system is recommended for this leachate.

Diterpenoid alkaloids from Delphinium gracile

Two highly oxygenated hetisine-type diterpenoid alkaloids, delphigraciline (1), 14-hydroxyhetisinone N-oxide (2), and the norditerpenoid alkaloid 8-methoxykarakoline (3), were isolated from a neutral extract of Delphinium gracile. Their structures were elucidated on the basis of spectroscopic data and by comparison with previously reported spectroscopic data of similar alkaloids. Their antiparasitic and insecticidal activities are also discussed.

Intravitreal triamcinolone acetonide injection in blind painful eyes. Intraocular steroids as a treatment for blind painful red eyes

PURPOSE

Phthisis bulbi results from different ocular conditions. We evaluated intravitreal triamcinolone acetonide as a treatment option in blind painful eyes.

METHODS

Thirty-one patients with unilateral phthisis were randomly divided into two groups. Group A received 0.3 ml (12.5 mg) triamcinolone acetonide intravitreally and Group B 0.3 ml balanced salt solution after retrobulbar anesthesia. Treatment success was assessed by subjective response to pain and clinically by biomicroscopic evaluation of conjunctival congestion. Tonometry was done before and after treatment. Follow-ups were at 24 hours, 3 weeks, 3 and 6 months, and 1 and 2 years.

RESULTS

Throughout the two-year follow-up, only two patients in Group A reported pain after the procedure and were retreated, one at week 4 and the other at week 7. Conjunctival congestion was significantly lower in Group A. Two patients with hypotony before treatment had normal tension after triamcinolone. All Group B patients were reinjected with triamcinolone because pain continued after balanced salt solution injection. No severe complications were found.

CONCLUSIONS

Intravitreal triamcinolone acetonide may be effective and safe for treating blind painful eyes.

The role of strategic attention deployment in development of self-regulation: predicting preschoolers' delay of gratification from mother-toddler interactions

Toddlers' use of effective attention deployment strategies to cope with separation from the mother and with maternal behavior predicted the use of effective delay-of-gratification strategies at age 5, even though the contexts, measures, and manifest behaviors were different. Toddlers who used distraction strategies during a brief separation from the mother were able, at age 5, to delay immediate gratification longer for more valued rewards. Toddlers who explored at a distance from a controlling mother when she tried to engage the child also delayed longer and used more effective delay strategies at age 5, compared with toddlers who did not distance themselves. Toddlers whose mothers were not controlling showed the opposite pattern: Those who did not distance themselves from the mother's bids had longer preschool delay times and more effective strategies. Strategic attention deployment was shown to be an enduring self-regulatory skill visible in early development across domains, measures, and over time.

Long-term treatment of spontaneously hypertensive rats with losartan and electrophysiological remodeling of cardiac myocytes

OBJECTIVE

Cardiac hypertrophy due to pressure overload is associated with several cellular electrophysiological alterations such as prolongation of action potential duration (APD), decrease in transient outward current (Ito) and occurrence of the pacemaker current I(f). These alterations may play a role in sudden arrhythmic death, which is a major risk factor in myocardial hypertrophy and failure. Since angiotensin II is a key signal for myocyte hypertrophy, we tested if an 8-week treatment of old spontaneously hypertensive rats (SHR) with the antagonist of type-1 angiotensin II receptor (AT1), losartan (10 mg/kg/day), was able to influence the cellular electrophysiologic remodeling associated with cardiac hypertrophy.

METHODS

Left ventricular myocytes were isolated from control (CTR) or losartan-treated (LOS) 18-month old SHR. Patch-clamped LVM were superfused with a normal Tyrode's solution (to measure action potential) or appropriately modified Tyrode's solution (to measure Ito and I(f)).

RESULTS

Heart weight to body weight ratio (HW/BW) was significantly smaller in LOS (5.69 +/- 0.25 mg/g) than in CTR rats (6.67 +/- 0.37 mg/g; P < 0.05). Membrane capacitance, an index of cell size, was significantly reduced in LOS (342 +/- 12, n = 92) vs. CTR (422 +/- 14 pF, n = 96, P < 0.001). APD was significantly shorter in LOS than in CTR (at -60 mV: 197 +/- 23 vs. 277 +/- 19 ms, n = 28, P < 0.001); this effect was paralleled by a larger maximum Ito density in the LOS group (LOS: 15.1 +/- 1.4 pA/pF, CTR: 10.0 +/- 0.8 pA/pF) (n = 27, P < 0.02). I(f), elicited by hyperpolarizing steps (range: -60 to -130 mV), was consistently recorded in SHR cells; however, its maximal specific conductance was significantly lower in LOS than in CTR rats (28.6 +/- 3.6 vs. 54.2 +/- 8.0 pS/pF, n = 55, P < 0.001). Voltage of half-maximal activation (V1/2) of both Ito and I(f) was unchanged by the treatment.

CONCLUSIONS

AT1 receptor blockade with losartan prevents the development of myocyte hypertrophy and associated electrophysiological alterations in old SHR.

Modulation of the pacemaker current If by beta-adrenoceptor subtypes in ventricular myocytes isolated from hypertensive and normotensive rats

OBJECTIVE

Both beta 1- and beta 2-adrenoceptors (beta 1-AR and beta 2-AR) are functionally present in human and rat ventricular myocytes. The two receptor subtypes are differently regulated during the development of myocardial hypertrophy and failure. I(f) is expressed in human and rat ventricular myocytes. In hypertrophied myocytes isolated from old spontaneously hypertensive rats (SHR) the density is much larger than in age-matched normotensive Wistar Kyoto (WKY). Due to the possible relevance of I(f) as an arrhythmogenic mechanism in the rat and human ventricle, we studied and compared the effects of beta 1-AR and beta 2-AR stimulation on I(f) in both hypertrophied and normal left ventricular myocytes of 18-month old SHR and WKY.

METHODS

The whole-cell configuration of the patch-clamp technique was employed. Noradrenaline (NA, 1 microM) was used to stimulate beta 1-AR and isoprenaline (ISO, 1 microM) in the presence of the beta 1-AR antagonist CGP 20712A (0.1 microM) to stimulate beta 2-AR.

RESULTS

In SHR, NA increased I(f) by causing a 10.8 +/- 0.9 mV (n = 10) positive shift in the voltage of maximal activation (V1/2); this effect was completely reversed by CGP 20712A. beta 2-AR stimulation was effective in seven out of 13 cells tested, where it caused a small positive shift in V1/2 (4.0 +/- 1.7 mV). Cyclopentyladenosine (CPA), a selective A1-receptor agonist, reversed the effect of NA; the antiadrenergic action of CPA was abolished in cells pre-incubated with pertussis toxin (PTX) to block inhibitory G proteins (Gi). In PTX-treated cells the shift in V1/2 caused by both beta 2-AR (9.6 +/- 1.7 mV, n = 6, p < 0.05) and beta 1-AR (17.6 +/- 1.9 mV, n =7, p < 0.05) was significantly greater than in control cells. Both beta-AR subtypes modulated I(f) activation also in WKY: beta 1-AR shifted V1/2 by 16.0 +/- 1.4 mV (n = 15) and beta 2-AR by 4.2 +/- 1.1 mV (n = 7). However, in PTX-treated WKY cells only the beta 2-AR effect was potentiated (shift in V1/2: 11.4 +/- 1.4 mV, n = 9, p < 0.01), while the beta 1-AR response was unchanged (18.9 +/- 4.2 mV, n = 5, n.s.).

CONCLUSIONS

I(f) expressed in SHR hypertrophied ventricular myocytes is modulated by catecholamines mainly through the stimulation of the beta 1-AR subtype. The beta 1-AR response is, however, significantly lower than that observed in myocytes from normotensive rats, probably as a consequence of the presence of an increased inhibitory activity of Gi proteins. This post-receptorial control may be seen as a mechanism to limit the arrhythmogenicity of beta-AR stimulation in myocardial hypertrophy and failure.

Creative Teams: An Experiential Activity

BACKGROUND

Staff development educators in a Department of Education & Development were seeking a creative activity to reinforce the qualities of effective teams.

METHOD

Staff development educators developed an experiential activity that provides an opportunity to observe team behaviors by introducing several glitches into a goal-oriented team project. Later, observed team behaviors were explored with the group.

RESULTS

The activity allowed participants to practice collaboration, communication, and problem-solving skills while functioning as a team.

CONCLUSION

This activity, which is easily adaptable to any audience, creatively integrates the principles of adult learning to provide participants with an opportunity to discuss and practice behaviors necessary for teamwork in the current health care settings.

Effect of chicken age on the nutritive value of diets with graded additions of full-fat sunflower seed

1. Diets containing increasing amounts (80, 160 and 240 g/kg) of hulled full-fat sunflower seed (HFFSS) were evaluated for digestibility of nutrients and AMEn content with broiler chickens at 2 different ages (10 to 12 d and 27 to 29 d). 2. The age of chickens and dietary concentration of HFFSS had no major effect on the apparent digestibility of protein N and single amino acids. The differences observed were generally small and attained statistical significance only with glutamic acid, histidine, arginine, phenylalanine and isoleucine digestibilities. 3. The age effect on the apparent digestibility coefficients for crude fat and total fatty acids was dependent on the dietary concentration of HFFSS. Significant interactions between age and inclusion rate were observed for fat and individual fatty acids digestibilities. 4. AMEn (MJ/kg) increased significantly as the inclusion level of HFFSS increased. However, AMEn content was not affected by bird age or by the interaction between age and inclusion rate.

A unique familial leukodystrophy with adult onset dementia and abnormal glycolipid storage: a new lysosomal disease?

Two adult siblings with early onset dementia are described. At presentation, in their early 30s, they showed poor judgment and disinhibition. A progressive dementia ensued over several years. Brain MRI disclosed diffusely increased T2 signal in the cerebral white matter, suggestive of a leukodystrophy. Numerous lysosomal enzyme assays including leucocyte arylsulphatase A and galactocerebrosidase activities, plasma and fibroblast very long chain fatty acid concentrations, and urinary sulphatide concentrations were normal, as were CSF analyses. A brain biopsy disclosed periodic acid Schiff (PAS) and Sudan black positive material in perivascular macrophages which, by electron microscopy, consisted of stacks of straight or curvilinear paired membranes within angulate lysosomes, indicative of abnormal glycolipid accumulation. The combination of clinical, radiological, biochemical, and pathological features of this degenerative disease is not consistent with that of any of the known leukodystrophies or lysosomal storage disorders. These findings suggest a previously undescribed familial glycolipid storage disorder causing an adult onset leukodystrophy and presenting with behavioural symptoms that mimic a psychiatric disorder.

Mycobacterium Chelonae Keratitis Following Laser in situ Keratomileusis

Corneal infection after laser in situ keratomileusis (LASIK) is rare. However, surgical trauma or breakdown of epithelium increases the risk of surface infection. We present the case of a 45 year old woman who developed keratitis due to Mycobacterium chelonae 1 month after LASIK with the Mini-Laser Sight 2000 excimer laser. After an initial improvement following antibiotic therapy the infection progressed until it was necessary to perform penetrating keratoplasty, with a successful result.

The apical submembrane cytoskeleton participates in the organization of the apical pole in epithelial cells

In a previous publication (Rodriguez, M.L., M. Brignoni, and P.J.I. Salas. 1994. J. Cell Sci. 107: 3145-3151), we described the existence of a terminal web-like structure in nonbrush border cells, which comprises a specifically apical cytokeratin, presumably cytokeratin 19. In the present study we confirmed the apical distribution of cytokeratin 19 and expanded that observation to other epithelial cells in tissue culture and in vivo. In tissue culture, subconfluent cell stocks under continuous treatment with two different 21-mer phosphorothioate oligodeoxy nucleotides that targeted cytokeratin 19 mRNA enabled us to obtain confluent monolayers with a partial (40-70%) and transitory reduction in this protein. The expression of other cytoskeletal proteins was undisturbed. This downregulation of cytokeratin 19 resulted in (a) decrease in the number of microvilli; (b) disorganization of the apical (but not lateral or basal) filamentous actin and abnormal apical microtubules; and (c) depletion or redistribution of apical membrane proteins as determined by differential apical-basolateral biotinylation. In fact, a subset of detergent-insoluble proteins was not expressed on the cell surface in cells with lower levels of cytokeratin 19. Apical proteins purified in the detergent phase of Triton X-114 (typically integral membrane proteins) and those differentially extracted in Triton X-100 at 37 degrees C or in n-octyl-beta-D-glycoside at 4 degrees C (representative of GPI-anchored proteins), appeared partially redistributed to the basolateral domain. A transmembrane apical protein, sucrase isomaltase, was found mispolarized in a subpopulation of the cells treated with antisense oligonucleotides, while the basolateral polarity of Na+-K+ATPase was not affected. Both sucrase isomaltase and alkaline phosphatase (a GPI-anchored protein) appeared partially depolarized in A19 treated CACO-2 monolayers as determined by differential biotinylation, affinity purification, and immunoblot. These results suggest that an apical submembrane cytoskeleton of intermediate filaments is expressed in a number of epithelia, including those without a brush border, although it may not be universal. In addition, these data indicate that this structure is involved in the organization of the apical region of the cytoplasm and the apical membrane.

Radiologic-Pathologic Conference of Children's Hospital Boston: scalp mass in a child following treatment for craniopharyngioma

A five-and-a-half-year-old boy with a history of craniopharyngioma presented with an enlarging scalp mass. The clinical history, CT images, histological findings and relevant discussion are presented.

Cyclic AMP modulates the rate of ‘constitutive’ exocytosis of apical membrane proteins in Madin-Darby canine kidney cells

Madin-Darby canine kidney and other epithelial cell lines (e.g. Caco-2, MCF-10A and MCF-7) develop intracellular vacuoles composed of apical membrane displaying microvilli (VACs) when impaired from forming normal cell-to-cell contacts. In a previous publication, we showed that VACs are rapidly exocytosed upon treatment with 8-Br-3′,5′-cyclic adenosine monophosphate (8-Br-cAMP), a membrane-permeable analog of cAMP, and that this exocytosis correlates with variations in the cellular cAMP concentration in response to the cell-cell contacts. In the present work, we tested the hypothesis that cAMP may be a positive modulator of the ‘constitutive’ exocytic pathway. To mimic conditions in cells with incomplete intercellular contacts, the intracellular levels of cAMP were decreased by means of two independent approaches: (i) pores were induced in the plasma membrane with the polypeptidic antibiotic subtilin, thus allowing small molecules (including cAMP) to permeate and move out of the cytoplasm; and (ii) adenylate cyclase and protein kinase A were blocked with specific inhibitors. In all cases, the intracellular levels of cAMP were measured and, in porated cells, equilibrated to simulate the corresponding physiological intracellular concentrations. The decrease in cAMP within the physiological range resulted in a decreased rate of transport of an apical marker of the constitutive pathway (influenza virus hemagglutinin) from the trans-Golgi network to the apical plasma membrane. Likewise, the delivery of a number of cellular apical proteins to the plasma membrane was retarded at low cAMP concentrations. The inhibitors of adenylate cyclase failed to block basolateral delivery of vesicular stomatitis virus G protein. This differential modulatory effect may represent a differentiation-dependent control of the insertion of apical membrane in epithelial cells.

Nitric oxide generation during cellular metabolization of the diabetogenic N-methyl-N-nitroso-urea streptozotozin contributes to islet cell DNA damage

The N-methyl-N-nitroso-urea streptozotocin is an antibiotic with diabetogenic, carcinogenic and antitumor activity thought to act via alkylation of DNA and proteins. Evidence points to a release of bioactive nitric oxide (NO) from streptozotocin as an additional cytotoxic activity of this drug. Here we show by EPR spectroscopy, that NO is not generated during spontaneous decay of streptozotocin but that its metabolization in rat hepatocytes and pancreatic islet cells yields NO. This NO formation is not due to a NO synthase (NOS) activity since NO formation in hepatocytes in the presence of streptozotocin is not blocked by the NOS inhibitor NG-methyl-L-arginine. By iNOS-specific RT-PCR no positive signal for specific mRNA presence was obtained in streptozotocin-treated cells, proving that iNOS activity was not induced during cell isolation procedures and did not account for the NO release. Furthermore, early DNA-strand breaks induced either by SZ or by the NO donor nitroprusside were both significantly reduced in the presence of an intracellular NO scavenger. In contrast, DNA damage found after incubation with the purely alkylating agent methylmethanesulfonate was not inhibited by the NO trap. These results prove that intracellular formation of NO occurs during degradation of SZ within cells. This NO appears to contribute significantly to streptozotocin-induced cytotoxicity.

Generic immunoassay of corticosteroids with minimum pre-treatment of urine samples

A generic, rapid and sensitive enzyme linked immunosorbent assay (ELISA) test has been developed which allows large-scale simultaneous testing of synthetic corticosteroids viz., flumethasone, dexamethasone and betamethasone. This assay can be directly applied to diluted urine samples (1 + 9) without hydrolysis of glucuronide or sulfate conjugates or any other treatment of samples. The polyclonal antibody was obtained by immunizing sheep with a flumethasone derivative linked to human serum albumin. This polyclonal antibody displayed high-reactivity with several synthetic corticosteroids whilst endogenous corticosteroids such as cortisol gave very low cross-reactivity (< 0.5%). Sensitivities obtained in this assay were 2.5, 3.1 and 12.5 ng ml-1 for flumethasone, dexamethasone and betamethasone, respectively. The ability of this assay to detect several synthetic corticosteroids was demonstrated by testing urine samples from horses to which the drugs had been administered.

Nitric oxide toxicity in islet cells involves poly(ADP-ribose) polymerase activation and concomitant NAD+ depletion

Previous studies have shown that DNA strand breaks are an early consequence of nitric oxide toxicity in pancreatic islet cells. We show here that exposure of islet cells to chemical NO donors causes the formation of ADP-ribose polymers in cell nuclei, with concomitant depletion of intracellular NAD+. Islet cell lysis was largely prevented by the ADP-ribosylation inhibitors nicotinamide, 3-aminobenzamide, and 4-amino-1,8-naphthalimide, the latter being a potent new-generation compound with high selectivity for poly(ADP-ribosyl)-ation. These findings indicate a key role of poly(ADP-ribose) polymerase activation in NO toxicity in islet cells.

Pancreatic islet cells are highly susceptible towards the cytotoxic effects of chemically generated nitric oxide

To compare the sensitivity of different mammalian cell types towards the cytotoxic action of nitric oxide, freshly isolated rat pancreatic islet cells, hepatocytes, resident and activated macrophages, cultured aortic endothelial cells and two murine tumor cell lines were tested for susceptibility towards exogenous nitric oxide. As sources for nitric oxide nitroprusside, S-nitroso-N-acetyl-penicillamine and the sydnonimine-derivative SIN-1 were used. These generate nitric oxide by different mechanisms and kinetics. Among the cell types tested we found large differences in their susceptibility towards the three nitric oxide donors. Islet cells were by far the most sensitive of the investigated cells and were completely lysed by all three nitric oxide donors. Hepatocytes and endothelial cells were sensitive towards nitroprusside but relatively resistant towards toxicity of SIN-1 and S-nitroso-N-acetyl-penicillamine. Activated and resident macrophages were lysed by SIN-1, whereas high concentrations of nitroprusside and S-nitroso-N-acetyl-penicillamine led to partial cell lysis only. The tumor cell lines were both lysed by SIN-1 but showed differences in their sensitivity towards S-nitroso-N-acetyl-penicillamine. Nitric oxide, which is produced in large amounts during infection and inflammation, may play an important role in the destruction of islet cells during insulitis leading to insulin-dependent diabetes mellitus.

Transgenic mouse model for neurocristopathy: Schwannomas and facial bone tumors

We have characterized a strain of double transgenic mice with simian virus 40 large tumor antigen and prokaryotic lacZ under the control of the myelin basic protein promoter that develops spindle-cell sarcomas and osteogenic sarcomas at 5-7 months of age. Although poorly differentiated, the spindle-cell sarcomas were characterized as malignant Schwannomas based on their neural association, the presence of basal lamina, and expression of Schwann cell-specific genes. The osteogenic sarcomas were often multiple and appeared predominantly in the facial bones, less frequently in the ribs and vertebral column, and only rarely in the appendicular skeleton. Benign osteoblastic lesions were often observed adjacent to these sarcomas. Both the osteoblastic cells in the facial skeleton and Schwann cells are regarded as neural crest derivatives. The biological properties and anatomical location of these tumors suggest that they may share a common origin from the neural crest or its derivatives. R.P. Bolande [Hum. Pathol. (1974) 5, 409-429] introduced the term neurocristopathy as a unifying concept to describe such lesions arising from the neural crest or its derivatives. Cell lines established from both bone and Schwann cell tumors arising in these transgenic mice express simian virus 40 large tumor antigen mRNA as well as functional large tumor antigen. Such cell lines are potentially valuable in the search for markers that identify mammalian neural crest derivatives.

Exocytosis of vacuolar apical compartment (VAC) in Madin-Darby canine kidney epithelial cells: cAMP is involved as second messenger

Vacuolar apical compartment (VAC) is a transient organelle originally observed in Madin-Darby canine kidney (MDCK) epithelial cells impaired from forming cell-cell contacts. VACs are large vacuoles which contain microvilli and apical plasma membrane markers (among others, a 184-kDa plasma membrane protein, AP2), but exclude basolateral membrane markers. Upon reestablishment of cell-cell contacts, VACs are rapidly (within 1 h) exocytosed toward intercellular spaces, after which the apical plasma membrane drifts toward its final destination (Vega-Salas, Salas, and Rodriguez-Boulan. 1988. J. Cell Biol. 107, 1717-1728). In this work, we studied the role of cAMP as a mediator for the exocytosis of VACs. We shifted confluent cells from low to normal calcium medium (thus reestablishing cell-cell contacts and causing VAC exocytosis), a shift which resulted in a significant rise of cellular levels of both total intracellular and protein-bound cAMP. The 8-Br analog of cAMP (8-Br-cAMP) (5-50 microM) caused externalization of the intracellular compartment of AP2 as measured by radioimmunoassay. A similar effect was observed with 3-isobutyl-1-methylxanthine. 8-Br-cAMP also caused the appearance of AP2-positive VAC images in nonpermeabilized cells, namely, VACs that become accessible to extracellular antibodies upon fusion with the plasma membrane. Lanthanum, which abolishes the peak of intracellular free calcium during a calcium switch, failed to block the exocytosis. On the other hand, 12-O-tetradecanoylphorbol-13-acetate induced only a modest exocytic response. Finally, 8-Br-cAMP induced VAC exocytosis in sparse MDCK cells grown in normal calcium medium. These data indicate that cAMP is a mediator between the extracellular signal provided by cell-cell contacts and VAC exocytosis.

Cytotoxicity of activated rat macrophages against syngeneic islet cells is arginine-dependent, correlates with citrulline and nitrite concentrations and is identical to lysis by the nitric oxide donor nitroprusside

Lysis of rat islet cells by syngeneic activated macrophages in vitro can be completely inhibited by the nitric oxide-synthase-inhibitor NG-methyl-L-arginine. This inhibition can be reversed by an excess of L-arginine. Time-dependent lysis of islet cells by activated macrophages is accompanied by increasing concentrations of nitrite and citrulline in the culture medium both of which are measures of nitric oxide formation derived from L-arginine. Lysis of isolated islet cells and disintegration of isolated whole islets is also obtained within 15 h by culture in the presence of the nitric oxide generating vasodilator sodium nitroprusside. We thus conclude that nitric oxide is extremely toxic for islet cells and that nitric oxide alone and in the absence of other macrophage-generated potentially toxic products can rapidly and completely kill islet cells.

[A new myoplasty method using the temporal muscle and cartilage allograft with the perichondrium]

The authors have for the first time achieved good results in experimental operations performed in 2 cadavers and 8 laboratory animals. A female patient suffering from progressive facial hemiatrophy was operated on with good results. The authors have revealed that facial deformation associated with Parry-Romberg's syndrome may be eliminated by myoplasty with the temporal muscle combined with transplantation of the allocartilage covered with perichondrium.

Structure and serological properties of the capsular K11 antigen of Escherichia coli O13:K11:H11

The capsular K11 antigen of Escherichia coli contains glucose, fructose, and phosphate in the molar ratios 2:1:1, and a backbone of -4)-beta-D-glucopyranosyl-(1----4)-alpha-D-glucopyranosyl phosphate-(1----to which beta-D-fructofuranose is linked at position 3 of the beta-D-glucopyranosyl residue. The fructose, which is the immunodominant sugar of the K11 antigen, is released from the polysaccharide under mild acidic conditions (70 degrees, pH 5.0).

Cognitive person variables in the delay of gratification of older children at risk

The components of self-regulation were analyzed, extending the self-imposed delay of gratification paradigm to older children with social adjustment problems. Delay behavior was related to a network of conceptually relevant cognitive person variables, consisting of attention deployment strategies during delay, knowledge of delay rules, and intelligence. A positive relationship was demonstrated between concurrent indexes of intelligence, attention deployment, and actual delay time. Moreover, attention deployment, measured as an individual differences variable during the delay process, had a direct, positive effect on delay behavior. Specifically, as the duration of delay and the frustration of the situation increased, children who spent a higher proportion of the time distracting themselves from the tempting elements of the delay situation were able to delay longer. The effect of attention deployment on delay behavior was significant even when age, intelligence, and delay rule knowledge were controlled. Likewise, delay rule knowledge significantly predicted delay time, even when age, attention deployment, and intelligence were controlled.

Cognitive person variables in the delay of gratification of older children at risk

The components of self-regulation were analyzed, extending the self-imposed delay of gratification paradigm to older children with social adjustment problems. Delay behavior was related to a network of conceptually relevant cognitive person variables, consisting of attention deployment strategies during delay, knowledge of delay rules, and intelligence. A positive relationship was demonstrated between concurrent indexes of intelligence, attention deployment, and actual delay time. Moreover, attention deployment, measured as an individual differences variable during the delay process, had a direct, positive effect on delay behavior. Specifically, as the duration of delay and the frustration of the situation increased, children who spent a higher proportion of the time distracting themselves from the tempting elements of the delay situation were able to delay longer. The effect of attention deployment on delay behavior was significant even when age, intelligence, and delay rule knowledge were controlled. Likewise, delay rule knowledge significantly predicted delay time, even when age, attention deployment, and intelligence were controlled.

Structure and serological characteristics of the capsular K4 antigen of Escherichia coli O5:K4:H4, a fructose-containing polysaccharide with a chondroitin backbone

The chemical structure of the K4-specific capsular polysaccharide (K4 antigen) of Escherichia coli O5:K4:H4 was elucidated by composition, carboxyl reduction periodate oxidation methylation nuclear-magnetic-resonance spectroscopy and enzymatic cleavage. The polysaccharide consists of a backbone with the structure----3)-beta-D-glucuronyl-(1,4)-beta-D-N-acetylgalactosaminyl(1- to which beta-fructofuranose is linked at C-3 of glucuronic acid. Mild acid hydrolysis liberated fructose and converted the K4 antigen into a polysaccharide which has the same structure as chondroitin. The defructosylated polysaccharide was a substrate for hyaluronidase and chondroitinase. The serological reactivity of the K4 polysaccharide was markedly reduced after defructosylation.

Comparative structural elucidation of the K18, K22, and K100 antigens of Escherichia coli as related ribosyl-ribitol phosphates

The structures of the capsular K18, K22, and K100 antigens of E. coli O23:K18:H15, O23:K22:H15, and O75:K100:H5, respectively, were elucidated by determination of composition, 1H-, 13C-, and 31P-n.m.r. spectroscopy, periodate oxidation, alkaline hydrolysis followed by incubation with alkaline phosphatase, and methylation analysis of the polymers and their neutral fragmentation products. The polymers are poly(ribosyl-ribitol phosphates) related to the capsular antigen of H. influenzae (Hib). The K22 antigen has the repeating unit -P-2)-beta-Rib-(1----2)-RibOH-(5-, and the K18 antigen has the same polymer chain with partial 3-O-acetylation of the ribose moiety. The K100 antigen consists of repeating units of -P-3)-beta-Rib-(1----2)-RibOH-(5- and seems to have a secondary structure different from that of the other antigens. Together with the Hib capsular antigens, the structure of which was reported as -P-3)-beta-Rib-(1----1)-RibOH-(5-, these capsular antigens represent a structurally related group of capsular polymers.

Adjusting delay to reinforcement: comparing choice in pigeons and humans

Indifference functions of amount and delay of reinforcement were compared for pigeon and human subjects by using Mazur's (1987) adjusting delay procedure. A model similar to the matching law (the simple reciprocal model), a hyperbolic model, three modified versions of the hyperbolic model, and a negative exponential model were evaluated. In Experiment 1 the subjects were pigeons, and in Experiments 2 and 3 the subjects were humans. In order to make the nonhuman and human situations more comparable, in Experiments 2 and 3 the reinforcer (points exchangeable for money) was discounted at a constant rate during the delay periods. The rate of this discounting varied between Experiments 2 and 3. The results of all three experiments demonstrated that a power function transformation of the hyperbolic model (in which 1 is added to the delays in the denominator of the simple reciprocal model) provided the best description of both nonhuman and human data.

Qualitative assessment of vaginal microflora during use of tampons of various compositions

The effect of vaginal tampons on the microbial flora during menstruation has recently been studied by several investigators. However, little information regarding the qualitative effects attributable to particular tampon fibers is available. The purpose of the present study was to compare the effects of polyacrylate rayon tampons and cotton-viscose rayon blend tampons on the qualitative bacterial counts obtained from tampons and concomitant vaginal swabs and to determine whether either of these tampon types alters the qualitative makeup of the vaginal microflora when compared with the microflora in the same women using all-cotton tampons or external catamenial pads. Tampon and swab samples were obtained as described previously (A. B. Onderdonk, G. R. Zamarchi, M. L. Rodriguez, M. L. Hirsch, A. Muñoz, and E. H. Kass, Appl. Environ. Microbiol. 53:2774-2778). The genus and species of the six dominant bacterial species in each sample were identified, if possible. A statistical evaluation of the qualitative makeup of the microflora revealed that the same numerically dominant phenotypes were present regardless of sample type, sample time, or catamenial product. Predictable changes in total numbers among the dominant species were also noted when the data were evaluated by day of menstrual cycle. The correlation between the total numbers of each dominant species present was evaluated by day of cycle, and the findings are discussed.

Quantitative assessment of vaginal microflora during use of tampons of various compositions

Although the effect of vaginal tampons on the microbial flora during menstruation has recently been studied by several investigators, quantitative effects attributable to particular tampon fibers have received less attention. The purposes of the present study were (i) to determine and then to compare the effects of polyacrylate rayon tampons and viscose rayon tampons on the normal vaginal flora, (ii) to compare quantitative bacterial counts obtained from these tampons with those obtained from concomitant vaginal swabs, and (iii) to determine whether either of these tampon types alters the vaginal microflora when compared with the microflora in the same women using all-cotton tampons or external catamenial pads. Tampon and swab samples were obtained at predetermined times from 18 women for an average of seven menstrual cycles. Samples consisting of swabs from women wearing menstrual pads were compared with swab and tampon samples taken at predetermined times during the menstrual cycle from women using cotton, polyacrylate rayon, or viscose rayon tampons. Samples were analyzed for total aerobic, facultative, and anaerobic bacterial counts. Statistical evaluation of the results indicated that, on the whole, total bacterial counts decreased during menstruation and that the numbers of bacteria in tampons tended to be lower than those in swab samples taken at the same time. The tampon type had little effect on the vaginal microflora.

Hydrogen bonds between protein side chains and phosphates and their role in biological calcification

Poly(L-histidine)-phosphate (H2PO4-, HPO4(2-)) and poly(L-glutamate)-phosphate systems (residue/phosphate, 1:1) in the presence of Ca2+ are studied by infrared spectroscopy. In the poly(L-histidine)-phosphate systems N...HOP in equilibrium NH+...O-P hydrogen bonds are formed where most phosphate protons are found at the histidine ring. With an increase in the degree of hydration the proportion of the proton limiting structure NH+...O-P increases. In the poly(L-glutamate)-dihydrogen phosphate system most phosphate protons are found at the carboxylate groups. Different behavior is observed for poly(L-glutamate)-hydrogen phosphate mixtures, where the residence time of the phosphate proton at the hydrogen acceptor carboxylate group is very short. This residence time increases, however, with increasing humidity. All these results support the triphasic theory of biological calcification involving a tripartite protein-calcium-phosphate complex where these hydrogen bonds can be present. The behavior of these hydrogen bonds can also explain the formation of a nidus of calcium phosphate salts in calcium oxalate-containing urinary calculi.

Self-control in adult humans: variation in positive reinforcer amount and delay

In five experiments, choice responding of female human adults was examined, as a function of variations in reinforcer amount and reinforcer delay. Experiment 1 used a discrete-trials procedure, and Experiments 2, 3, 4, and 5 used a concurrent variable-interval variable-interval schedule. Reinforcer amount and reinforcer delay were varied both separately and together. In contrast to results previously reported with pigeons, the subjects in the present experiments usually chose the larger reinforcers even when those reinforcers were delayed. Together, the results from all the experiments suggest that the subjects followed a maximization strategy in choosing reinforcers. Such behavior makes it easy to observe self-control and difficult to observe impulsiveness in traditional laboratory experiments that use adult human subjects.

Antenatal diagnosis of mosaic trisomy 8 confirmed in fetal tissues

An aneuploid karyotype with an extra submetacentric C-group chromosome was observed in all metaphase cells in 5 of 24 primary amniotic fluid cell clones and in admixture with normal cells in two additional clones. Trisomy 8 was demonstrated by R-banding. The parents elected to terminate the pregnancy. Successful cultures were initiated from nine fetal tissues and aneuploid cells were observed in cultures derived from two separate sites in the skin.

Levamisole therapy for multiple warts

Levamisole, a wide-spectrum antiparasitic drug, increases cellular immunity in vivo and in vitro. Patients with verruca vulgaris may have defective cell mediated immune mechanisms. Levamisole was given to twenty-two patients with multiple warts, 5 mg/kg body weight on 3 consecutive days every fortnight. Patients' lymphocytes were studied for E-rosette formation before therapy. E-rosette counts were lower in patients compared with controls and a significant increase was obtained after in vitro incubation with levamisole. Seventeen patients were cured in 1-4 months, there were four failures and one patient showed marked improvement. It is concluded that patients with multiple warts have defective cell-mediated mechanisms as far as the E-rosette count is concerned and that levamisole increases in vitro E-rosette formation and is useful in the treatment of these patients.

Amniotic fluid cell mosaicism for presumptive trisomy 20

Trisomy for an F-like chromosome with banding characteristics of chromosome 20 was observed, respectively, in 25 and 8% of amniotic fluid cell clones in two cases of prenatal diagnosis for advanced maternal age. No such aneuploidy was found upon examination of fetal or postnatal tissues. In both instances there were no detectable malformation. It is suggested that propensity to nondisjunction for an F-like chromosome, not unlike tetraploidy, might be another characteristic of amniotic fluid cells in culture.

Mosaicism in amniotic fluid cell cultures: classification and significance

The last decade has witnessed increasing application of human cytogenetic technology to prenatal chromosome analysis. However, unlike the rather uniform peripheral blood T-lymphocyte system which has provided most of our experience in human cytogenetics, long-term amniotic-fluid cell cultures display extreme cellular heterogeneity and disproportionate growth of certain cell types as a consequence of clonal amplification. When they enter cell culture, many of these cells are approaching the terminal stages of their respective, life spans and may have accumulated chromosomal aberrations. Concern about the possibility of true fetal mosaicism seems warranted chiefly in situations were multiple colonies display potentially viable aberrations. Clonal analysis, preferably of multiple clonal types, and attention to details of clonal morphology are likely to minimize diagnostic errors and undue apprehension resulting from mosaicism in amniotic-fluid cell cultures.